Machine for molding concrete blocks



Dec. 9, 1952 DAVlEs EI-AL 2,620,541

MACHINE FOR MOLDING CONCRETE BLOCKS Filed Nov. 25, 1949 3 Sheets-Sheet lJNV ENTOR. M1 Zes. Dawes and 1952 M. DAVIES ETAL 2,620,541

' MACHINE FOR MOLDING CONCRETE BLOCKS Filed Nov. 25, 1949 s Shets-Sheet2 INVENTOR. Mi Zes Davies and Dec. 9, 1952 M. DAVIES ETAL 2,620,541

- MACHINE FOR MOLDING CONCRETE BLOCKS Filed Nov. 25, 1949 3 Sheets-Sheet5 a v i INVEZNTOR. M1285 Dc was and Patented Dec. 9, 1952 OFFICE OLDINGCONCRETE MAGHINEv FOR M BL OCKS MilesiDavies 'andFred Neth, Vancouver,Wash;

Application November 25, 1949; SerialtN0. 129, 38.8'

(Cl.v 25-41) 3 Claims. I Qur. invention-.relatesto. concrete blockforminmachines and. to; animprovement. in. the art. of trowelingsaidblocks to:produce a smoothfinish thereon.v

One of the principalobjectsof our invention is to provide a. machinewitha box-like mold having sides-andendsbut no bottom. A pallet un.-derlies'and seals the bottom of said mold. Said mold iscarried at theendsof pairs of elongated spring element-s whichare subject to fiexurealong a path which-is substantially vertical. Said mold isv providedwith vibrator means for partially supporting it and for shaking itrapidly. Thevib-rator means is provided with pivotal joints so that themovement of said mold is limited to the path defined by the flexure ofsaid spring elements. Ejecting mean-sis provided for said mold, which isoperable to discharge formed blocks through the open bottom of said moldalong a path substantially parallel with that defined by the flexureofsaid spring elements, and the vibration is continued while said blocksare being ejected so as to cause the sides and ends of said mold totrowel the abutting faces of said concrete blocks, previously formed insaid mold, while they are being ejected therefrom, to produce a smoothfinish thereon.

Further and. other details of our invention are further described inconnection with the accompanying drawings, in which:

Fig. 1 is a front elevation of a machine embodying our invention, withthe motor drive. therefor shown in dotted lines;

Fig. 2-is an end elevation of said machine, with portionsshown brokenaway to disclose the driving means which would otherwise be concealed;

Fig. 3. is an enlarged detailed view of the mold box of said machine,its supporting springs and a portion of the power driven vibratingmeans, themovement of said mold box being diagrammatically depicted bydouble-ended arrows applied to said drawing; and

Fig.4 is. an enlarged sectional view taken on the line 44 in Fig. 3.

The general details of our machine are similar to the machine.illustratedin the co-pending application for Letters Patent filedDecember 6, 1948., by Russell B. Nelson, Miles Davies, and Fred Neth,zbearing Serial No. 63.812 and entitled Method of and. Machine forMaking Concrete Blocks. Reference, is made. to said application for. thegeneral details of. said machine and the method of-operationthereoi.

Sufii'ce it to say that aconcrete block making machine. embodying the:features of our invention comprises a; rectangular. frame. Projectingfrom the front of. said frame are two pairs of base. members includingan upper pair 2 and a lower pair 3. Said base members have verticallyalined eyes formed therein for receivingthetubular sleeveswhichreciprocate therein. Thelower endsof. said. sleeves. are joinedtogether below the lower. base member 3'. by horizontal toggle beam 5,which is secured to said sleeves by bolts. The toggle beam issupportedat its center upon the upper end of, apiston rod 6., whichissecured thereto, andat. each endby a toggle mechanism as is shown inFigure 2. It is this toggle mechanism which actuates a pressure head 44to compress the mold contents during casting as will hereinafter bedescribed. The opposite endofthe piston rod is connected to a piston.which is movable vertically within a double-acting hydraulic stripper.cylinder 1. The stripper cylinder is secured. to an H-shapedbracket 8,which projects from the front of said frame. The bracketB isformedwithlaterally projecting flanges 9 on its upper edge to provide supportfor the upstanding pedestals I0 which. are secured thereto. A shoulderII. is. formed about each of. said pedestals intermediate. the endsthereof. Removable bumpers l2. each have a hollow end which slidablyengages the upper .end of the pedestals. A shoulder I3 is formedintermediate. the endsof said bumpers. Coil springs l4 encircle theengaged portions of said pedestals and bumpers, and. abut at their endsagainst the opposing faces of sai'dshoulders. In therelaxed position. ofsaid springs. the, telescoping ends of the pedestals. and bumpers arespaced apart, and may bemoved together by compressing the coil springsI4. The upper endsof the bumpers are arranged. to contact the togglebeam as the latter approaches its lowermost position. A pallet beam I5extends transversely betwee the sleeves 4 intermediate the upper and.lower base members, 2 and 3., respectively, and is se-.- cured thereto.since the toggle beam 5 and pallet beam. [5 are secured firmly to thesleeves 4, the units, so formed is here. referred to as the stripperassembly.- This assembly reciprocates vertically asthe doubleeactingcylinder 1 is actuated. A. platform Itv projects forwardly andrearwardly from the center of said beaml -Q0il springs l1, rest at thelower ends of said platform. and support at their upper ends a pallettable [8. Bolts extend axially through said springs, and slidablythrough holes provided. in the. platform and table. to. secure saidsprings in place. justmentl screws l-9. rest at their lower ends uponsaid platform, and support at their upper ends a pallet table 20.Adjustment screws l9 are provided upon the platform i6 for verticaladjustment, and are provided with lock nuts for securing said screws inany position desired. The adjustment screws are arranged to contact thepallet table I8 to prevent excessive rocking of the latter duringvibration. The pallet table is proportioned and arranged to support apallet upon which the concrete blocks are carried from the machine aftermanufacture. Accordingly, as the stripper assembly reciprocatesvertically, the pallet 20 reciprocates vertically.

A concrete block mold 22 is held suspended above the pallet table I8 bythe free ends of pairs of elongated spring members 23. Said springmembers preferably comprise a plurality of leaves 24, 25, 26, and 21.The spring leaves 24 and 25 are joined together by bolts 28 passingthrough tubular eyes 28 welded to the sides of the frame Similar bolts29 pass through tubular eyes 30 welded to the sides of said frame, andjoin spring leaves 26 and 21. Thus at each side of the frame are springelements, each comprising plural leaves which carry the mold 22. Saidspring elements are elongated flat strips of spring material, and areheld in substantial parallelism by means of said bolts and said tubulareyes. Said spring elements and the leaves thereof constitute cantilevermembers, supported at one end and with their free ends joined togetherby a screw element 3| which passes through the ends of each of saidleaves. Said leaves are spaced apart by spacers 32 encircling said screwelement and lying intermediate certain of the leaves of the springelements. That is to say, said spacers lie between the leaves 24 and 25,and between the leaves 25 and 26. Spacing the leaves 26 and 2'! apart isa pad eye 33, joined by capscrews 34 to the side of the concrete blockmold 22 at each side of the latter. The screw element 3! at each side ofthe concrete block mold 22 is joined by a connecting rod 35. The upperend of said connecting rod is bifuracted as at 35c, straddlin an eye 3laat the lower end of screw element 3|, and being joined thereto by a pin36. The lower end of each of said connecting rods is flattened and hasan eye 35b formed thereon. In the bore of said eye is an eccentric cam31 fixed to drive shaft 38. Thus said drive shaft rotates the eccentriccam, and the connecting rod is reclprocated back and forth. The movementof its upper bifurcated end 35a transmits motion to the screw element 3|and therewith to the concrete block mold which is joined thereto by thepad eye 33. The eccentric movement of the lower end of the connectingrod is not transmitted to said concrete block mold, due to the fact thatthe pin 36 journals ,in the bifurcated end 35 and thus movement of themold box is limited to the' path defined by the free end of the springele- 'ments 23. Because said spring elements are relatively long and aresecured at one end and are free at the end at which they carry theconcrete block mold, said mold is limited to more or less pure verticalmovement as is indicated by the double headed arrows in Fig. 3 of thedrawings. This is oneof the important features of our invention.

Said shaft 38 is driven by a pulley 39 joined to the drive pulley 40 ofthe motor 4| by belt 42.

The material of which said concrete blocks are made in our machine isdeposited from hopper 43 by feeding means which are not particularlypertinent to an understanding of our present invention, and which aredescribed in detail in the application for patent heretofore identified.We preferably provide a substantially dry mixture, and this flows intothe concrete block mold and is supported by the pallet 20 whichunderlies and seals the bottom thereof. That is to say, said concreteblock mold comprises ends and sides, is open at the top and bottom, andthe pallet 23 seals said bottom. When concrete blocks are being formedwithin said mold, the pressure head 44 enters through the top of themold and compresses the contents thereof between the head of saidpressure head and said pallet. Pressure isapplied to the material ofwhich said concrete blocks are made while said mold is being subjectedto vibration produced by the rotation of the drive shaft 38 actingthrough the connecting rods 35 to flex the elongated spring members ashas been commented upon.

Thereafterthe pallet 20 is lowered by the stripper assembly and theblocks have been compressed and vibrated so that they are firm and willnot crumble and collapse. The retraction of the pallet is in a verticalplane, and thus is parallel to the vibrational path effected by themovement of the connecting rods. The pallet is relatively slowly moveddownwardly, and the vibrational rate is quite high. Thus, while saidblocks are being ejected on the pallet the sides and ends of theconcrete block mold move rapidly over them to trowel them and to givethem a smooth surface. The truly linear vertical vibration of theconcrete block mold tends to produce excellent compaction of thematerial making up said concrete blocks while said blocks are within themold and are subject to vibration and pressure. The relatively slowwithdrawal of the pallets and therewith the concrete blocks supportedthereby, while said vertical vibration continues, tends to smooth andtrowel the sides of said concrete blocks without subjecting them to anydisruptive forces.

We claim:

1. In a machine for making concrete blocks, the combination of a frame,spring elements joined to said frame and subject to ilexure only along apath which is substantially vertical, a box-like mold having sides andends but no bottom partially supported by said spring elements, vibratormeans for shaking said mold rapidly, means for limiting the movement ofsaid mold to the path defined by the fiexure of said spring elements,and ejecting means for said mold, which ejecting means is operable todischarge formed blocks through the open bottom of said mold along apath substantially parallel with that defined by the flexure of saidspring elements, sa'id ejecting and vibrator means being operable at oneand. the same time so the block is vibrated during ejection, said springelements each comprising a plurality of leaves, spaced apart and joinedat spaced points along their length tocause them to flex together and inparallelism.

2. In combination with a casting machine having a frame, a, plurality ofelongated parallel leaf springs, each said spring having a first endsecured to said frame and a second end free to flex with respectthereto, said springs being secured in substantially horizontal planesto limit the flex of said second ends to a substantiallyverticaldirection, an open bottomed mold box. partially supported bysaid second ends, vibrator means for vibrating said mold in a sub-,stantially vertical direction as constrained by said second ends, saidvibrator means including a pair of connecting rods joined to said moldto limit the movement thereof to said substantially vertical direction,and ejecting means operable while said mold box is being vibrated toeject formed blocks through the open bottom of said mold box.

3. In combination with a casting machine having a frame, a, plurality ofparallel leaf springs each having a first end secured to the frame and asecond end free to flex with respect thereto, an open bottomed mold boxpartially supported upon said second ends, for movement therewith, amovable pallet underlying said mold box and defining a removable bottomtherefore, vibrator means for vibrating the mold box in a directionguided by the flex of said leaf springs, and ejecting means joined tosaid pallet to lower the same and eject a formed block through theREFERENCES CITED The following references are of record in the 10 fileof this patent:

UNITED STATES PATENTS Number Name Date 1,921,003 Romie Aug. 8, 19332,235,440 Mackert Mar. 18, 1941 2,298,446 7 White Oct. 13, 19422,397,695 Schutt Apr. 2, 1946 2,541,734 Akers Feb. 13, 1951

